fitted with a long, sharp steel ram in front, the advance was peculiarly adapted for this sort of work. in designing the ship this ram was calculated to be used against hostile vessels in war time, for the submarine was at first, as we know, destined for a government boat. now the ram was to serve a good turn.
to make sure that the attempt would be a success, the machinery of the craft was carefully gone over. it was found to be in perfect order, save for a few adjustments which were needed. then, as it was night, though there was no difference in the appearance of things below the surface, it was decided to turn in, and begin work in the morning. nor did the gold-seekers go to the surface, for they feared they might encounter a storm.
"we had trouble enough locating the wreck," said captain weston, "and if we go up we may be blown off our course. we have air enough to stay below, haven't we, tom?"
"plenty," answered the lad, looking at the gages.
after a hearty breakfast the next morning, the submarine crew got ready for their hard task. the craft was backed away as far as was practical, and then, running at full speed, she rammed the wreck. the shock was terrific, and at first it was feared some damage had been done to the advance, but she stood the strain.
"did we open up much of a hole?" anxiously asked mr. swift.
"pretty good," replied tom, observing it through the conning tower bull's-eyes, when the submarine had backed off again. "let's give her another."
once more the great steel ram hit into the side of the boldero, and again the submarine shivered from the shock. but there was a bigger hole in the wreck now, and after captain weston had viewed it he decided it was large enough to allow a person to enter and place a charge of dynamite so that the treasure ship would be broken up.
tom and the captain placed the explosive. then the advance was withdrawn to a safe distance. there was a dull rumble, a great swirling of the water, which was made murky; but when it cleared, and the submarine went back, it was seen that the wreck was effectively broken up. it was in two parts, each one easy of access.
"that's the stuff!" cried tom. "now to get at the gold!"
"yes, get out the diving suits," added mr. damon. "bless my watch-charm, i think i'll chance it in one myself! do you think the sharks are all gone, captain weston?"
"i think so."
in a short time tom, the captain, mr. sharp and mr. damon were attired in the diving suits, mr. swift not caring to venture into such a great depth of water. besides, it was necessary for at least one person to remain in the submarine to operate the diving chamber.
walking slowly along the bottom of the sea the four gold-seekers approached the wreck. they looked on all sides for a sight of the sharks, but the monster fish seemed to have deserted that part of the ocean. tom was the first to reach the now disrupted steamer. he found he could easily climb up, for boxes and barrels from the cargo holds were scattered all about by the explosion. captain weston soon joined the lad. the sailor motioned tom to follow him, and being more familiar with ocean craft the captain was permitted to take the lead. he headed aft, seeking to locate the captain's cabin. nor was he long in finding it. he motioned for the others to enter, that the combined illumination of the lamps in their helmets would make the place bright enough so a search could be made for the gold. tom suddenly seized the arm of the captain, and pointed to one corner of the cabin. there stood a small safe, and at the sight of it captain weston moved toward it. the door was not locked, probably having been left open when the ship was deserted. swinging it back the interior was revealed.
it was empty. there was no gold bullion in it.
there was no mistaking the dejected air of captain weston. the others shared his feelings, but though they all felt like voicing their disappointment, not a word could be spoken. mr. sharp, by vigorous motions, indicated to his companions to seek further.
they did so, spending all the rest of the day in the wreck, save for a short interval for dinner. but no gold rewarded their search.
tom, late that afternoon, wandered away from the others, and found himself in the captain's cabin again, with the empty safe showing dimly in the water that was all about.
"hang it all!" thought the lad, "we've had all our trouble for nothing! they must have taken the gold with them."
idly he raised his steel bar, and struck it against the partition back of the safe. to his astonishment the partition seemed to fall inward, revealing a secret compartment. the lad leaned forward to bring the light for his helmet to play on the recess. he saw a number of boxes, piled one upon the other. he had accidentally touched a hidden spring and opened a secret receptacle. but what did it contain?
tom reached in and tried to lift one of the boxes. he found it beyond his strength. trembling from excitement, he went in search of the others. he found them delving in the after part of the wreck, but by motions our hero caused them to follow him. captain weston showed the excitement he felt as soon as he caught sight of the boxes. he and mr. sharp lifted one out, and placed it on the cabin floor. they pried off the top with their bars.
there, packed in layers, were small yellow bars; dull, gleaming, yellow bars! it needed but a glance to show that they were gold bullion. tom had found the treasure. the lad tried to dance around there in the cabin of the wreck, nearly three miles below the surface of the ocean, but the pressure of water was too much for him. their trip had been successful.
